产ESBLs肺炎克雷伯菌AmpC酶的检测及耐药性分析

Analysis of the AmpC β-lactamas and antibiotic resistance of ESBLs-producing Klebsiella pneumoniae

目的了解深圳市人民医院产ESBLs肺炎克雷伯菌中产AmpC酶的情况及其耐药性。方法收集产ESBLs肺炎克雷伯菌临床株126株,应用Tris-EDTA纸片法检测AmpC酶。用琼脂稀释法测定菌株对11种抗生素的最低抑菌浓度(MIC)。结果126株ESBLs阳性的肺炎克雷伯菌中12株检出AmpC酶,检出率为9.5%。AmpC阳性菌株对头孢西丁、头孢他啶、氨曲南、氨苄西林/舒巴坦和阿莫西林/克拉维酸的耐药率达100%,对阿米卡星和哌拉西林/他唑巴坦的耐药率分别为83.3%和33.3%,其中头孢西丁、头孢他啶、氨曲南、阿莫西林/克拉维酸、阿米卡星和哌拉西林/他唑巴坦的耐药率显著高于AmpC阴性株(P<0.05)。结论深圳市人民医院产ESBLs肺炎克雷伯菌中检出AmpC酶阳性株,其耐药性强于单产ESBLs菌株。

Objective To understand the occurrence of AmpC β-lactamase and antibiotic resistance of ESBLs-producing Klebsiella pneumoniae isolates from Shenzhen People＇s Hospital.Method 126 ESBLs-producing Klebsiella pneumoniae clinical strains were collected,Tris-EDTA disk test was applied for detection of AmpC enzymes. Minimum inhibitory concentrations （MICs） of the strains 11 antibiotics against were determined by using agar dilution method.Result 12 of the 126 ESBLs-positive Klebsiella pneumoniae isolates were detected harboring AmpC enzymes,the detection rate being 9.5%. AmpC-positive strains showed 100% resistance to cefoxitin,ceftazidime,aztreonam,ampicillin/sulbactam and amoxicillin/clavulanic acid,while their resistance to amikacin and piperacillin/Tazobactam was 83.3% and 33.3% vespectively.Their resistance rate to cefoxitin,ceftazidime,aztreonam,amoxicillin / clavulanic acid,amikacin and piperacillin/tazobactam were significantly higher than those of AmpC-negative strains （P〈0.05）. Conclusion AmpC β-lactamase has been detected in ESBLs-producing Klebsiella pneumoniae isolates in Shenzhen People＇s Hospital,which provides the strains with stronger drug-resistance.